A concerted effort will be made to adapt the use of Nuclear Magnetic Resonance Spectroscopy (NMR) to the following areas of biochemical relevance. Experimental evidence for the proposed gamma-glutamyl cycle and its physiological role on the biochemical mechanism of amino acid transport will be studied by C13 and F19 NMR. An understanding of the exact function of the constituents of this cycle will have important biological and medical applications in the treatment of metabolic defects associated with this process. The role of metal ions in promoting catalytic activity of a variety of metalloenzymes will be studied by C13 and P31 NMR of inhibitors binding to the active site and of covalently bound labels in the vicinity of the enzymes' active site. An understanding of the role of the metal as an essential feature of these enzymes' structure and function is required before an in-depth understanding of the pathological disorders attributed to metal deficient states is possible (e.g. growth rate, pregnancy and birth). NMR spectral probes will be used to study the active site of enzymes which catalyze several transmethylation reactions. These enzymes catalyze the biosynthesis and utilization of methionine in a series of reactions which have important ramifications in cellular growth and replication. The physiological requirements of biological membranes will be studied by detection and characterization of possible catalytic sites for vesicle-vesicle fusion in synthetic vesicle systems using F19 NMR. An understanding of factors influencing stability here may lead to understanding and control of fusion in more complex systems e.g., cell-cell or virus-cell fusion.